Cushioning panel



y 1934- E. A. LEONARD 1,968,084.

CUSHIONING PANEL Filed July 11, 1932 fiwerzZ'afflzwa'rdaleomrd,

fiatenteri July 31 1934 urre STATES r 1,968,084 CUSHIONING PANEL Edward A. Leonard, Chicago, 111., assignor to 0renda Corporation, Chicago, 111., a corporation of Illinois Application July 11, 1932, Serial No. 621,892 3 Claims. 01. 217-26) This invention relates to cushioning panels, and

is illustrated as embodied in acomposite structure of two layers, one of which is so. shaped asto form a cushion, and the other of which is glued thereto to reinforce the same.

According to one featureof the invention, the

reinforcing sheet is perforated preferably with Whatever. their size, they'are best spaced slightly fairly large holes, thereby preventing the forma tion of sealed air cells.

One object of the invention is to provide a cushioning board for packing, insulation or the like, which will have the advantages of similar materials heretofore known, and which will have the added advantages of quicker drying qualities and better ventilation when used as packing material. In the past, when packing panels having sealed air cells were used for cold storage purposes the sealed cell would harbor heated air which'would be quite slow in giving off its heat, with the result that the complete refrigerating process would take a considerable time. According to the present invention, the sealed cells are avoided without undue loss of cushioning value, with the result that the cold air can circulate into the spaces which would otherwise be sealed air pockets.

In the manufacture of similar material with sealed air pockets a considerable quantity of the gluing material was exposed to the air within the pocket, but inasmuch as this air was trapped, the drying of the adhesive was necessarily slow. This objection has been partially overcome by avoiding the sealed air pockets.

Other objects of the invention will appear from the following description, drawing and claims.

.In the drawing, in which like numerals arev used for similar parts throughout,

Figure 1 is a plan view of a segment of one embodiment of my invention;

Figure 2 is a section through line 2-2 of Figure 1; and

Figure 3 is a section through line 33 of Figure 1.

Although my invention may take many forms, only one has been chosen for illustration. This form is made up of two layers of paper or cardboard 10 and 12, suitably stuck together. The layer 10 which may be called the cushion sheet is of corrugated form and is preferably made as illustrated with squares or other zones of raised surface completely surrounded by a depressed portion adapted to be pasted to the backing sheet 12. The raised portion may suitably comprise a square 14 in one plane, with ribs 16 extending across the square, the upper part of the ribs being nearly in the same plane if desired. The surrounding depressed portions 18 then form square borders around the raised portions. Thebacking sheet 12 is perforated in any suitable manner, with any suitable shapes of perforations. Prefe erably the perforations comprise the holes 20 which are desirably about to inches in diameter, but which may be even smaller or larger.

less than one-half the distance between the de pressed portions 18, so that no matter how the backing sheet is placed on the cushion sheet, there will always be four holes in each square. However, if the usual commercial practice is followed in the manufacture of these panels by forming a continuous strip of the cushion memher and gluing it to a continuous strip of the backing member, then the spacing of the holes may be different. With such a process it is possible to consistently center the backing sheet on the cushion sheet and therefore the holes may be spaced laterally in such a manner that longitudinalrows areuniformly located with respect to the depresed portions or grooves 18. Thus, in Figure 1 it is seen that there are two vertical (i. e longitu dinal) rowsto each square while in each vertical row the spacing is less than onehalf the width of the square, for the reason mentioned above. It is nqhpractical with present commercial processes to space the two sheets uniformly longitudinally. If preferred, the holes 20 5 may be simply punched instead of being out clean,

as this can be done with cheaper apparatus.

In commercial practice, the continuous cushion sheet is glued along its depressed'portions, as at 22, and is fed to the continuous backing sheet to 0 which it is then firmly pressed and pr ferably heated while the glue sets. As above discussed, the two sheets are fitted fairly exactly laterally but taken as they come longitudinally. Laterally they are so fitted that the rows of holes correspond 5 with the squares or plateau-like areas, as shown in Figure 1.

In the present form, the cushion panel does not have the sealed air chambers that were formerly considered very important. It has been found however that this is not necessary. The cushioning effect lost is not as great as was expected, and in fact is very small. The loss of strength is negligible since in either case the strengthening effect of the backing sheet was chiefly in the 1 prevention of spreading of the cushioning sheet and in serving as a limit to the depressibility of the raised portions of the cushionsheet. So long as thebacking sheet is sufficiently strong to prevent the spreading apart of the grooves 18, its

l the art.

chief function is accomplished. Due to the steepness and mutual reinforcing effect of the vertical walls 24, they yield very little to the pressure of an egg or the like on the center of the raised squares. These raised squares, due partly to their corrugated form, are very effective cushions. At the same time, air is permitted to circulate into the chambers beneath the squares, thereby causing quicker drying of the excess glue and more rapid refrigeration.

If it should be desired for any reason, either or both sheets may be saturated with asphalt or other waterproofing material to increase its effectiveness for insulating and similar purposes.

The term glue as here used, should be consid' ered as including asphalt or other suitable adhesives. The glue which is preferred, unless the sheets are saturated with asphalt, is a solution of silica and water.

It is to be understood that many other embodiments of the-invention, including some in improved form, will be apparent, and in the course of time more will be devised by those skilled in It is not desired that this invention be limited to the details described, for its scope includes all such forms or improvements as come Within the spirit of the following claims, construed as broadly as the prior art will permit.

What is claimed is:

1. An egg flat including a cushion sheet of approximately uniform thickness throughout having raised plateau-like sections at least an inch long on each side, said plateau-like sections being corrugated along their center portions and being bordered by deep intersecting grooves the walls of which reinforce one another at their corners, and a backing sheet secured to the under side of said grooves in such manner as to prevent the spreading apart of said grooves, said backing sheet being perforated with holes at least one of which is positioned to communicate with each of the spaces below said plateaus, said holes being of such size and so positioned as to leave in the backing sheet sufficient body below each of the plateaus to form a reserve support for the plateaus, said cushion sheet being formed of a stock which is too thin for reliable use in packing eggs except when reinforced as by said backing sheet.

2. An egg flat including a cushion sheet of approximately uniform thickness throughout having raised plateau-like sections at least an inch long on each side, said plateau-like sections being corrugated along their center portions and being bordered by deep intersecting grooves the walls of which reinforce one another at their corners, and a backing sheet secured to the under side of said grooves in such manner as to prevent the spreading apart of said grooves, said backing sheet being perforated with holes at least two of which are positioned to communicate with each of the spaces below said plateaus, said holes being of such size and so positioned as to leave in the backing sheet sufficient body below each of the plateaus to form a reserve support for the plateaus, said cushion sheet being formed of a stock which is too thin for reliable use in packing eggs except when reinforced as by said backing sheet; the perforations of said backing sheet being spaced in rows in one direction slightly less than one-half the distance between said grooves to insure the presence of at least two holes in each row between each pair of grooves, regardless of the relative positions of the two sheets in said direction.

3. An egg flat including an imperforate cushion sheet of approximately uniform thickness throughout having raised plateau-like sections at least an inch long on each side, said plateau-like sections being corrugated along their center portions and being bordered by deep intersecting grooves the walls of which reinforce one another at their corners, and a backing sheet secured to the under side of said grooves in such manner as to prevent the spreading apart of said grooves,

said backing sheet being perforated with holes at least one of which is positioned to communicate with each of the spaces below said plateaus, said holes being of such size and so positioned as to leave in the backing sheet sufficient body below each of the plateaus to form a reserve support for the plateaus, said cushion sheet being formed of a stock which is too thin for reliable use in packing eggs except when reinforced as by said backing sheet.

EDWARD A. LEONARD. 

